Refrigerator control



Feb 16, 1937.

F. E. BEEBE REFRIGERATOR CONTROL Filed Aug. 14; 193.4

JNVENTOR FREDRICK E. BEEBE ORNEYJ refrigerator.

Patented Feb. 1c, 1937 UNITED STATES PATENT OFFICE Application August 14, 1934, Serial No.v 739,741

13 Claims.

This invention relates to control mechanism and particularly to a type of temperature responsive control suitable for use in refrigeratin-g systems.

In refrigerating systems of the intermittent absorption type, the refrigerating fluid is evaporated in a boiler by the application of external heat and the vapor thus produced takes up heat in another part of the system, thus cooling the contents of the so-called frost chamber of the The external heat is usually applied to the boiler in some form of fluid fuel and the present invention relates to a manner of controlling the fiow of a fluid fuel in such a system. The quantity of vapor produced as the result of application of heat to the boiler will maintain the frost chamber at a suitable low temperature for a considerable period of time and it is the purpose of my invention to supply control mechanism which will shut off the flow of fuel when sufficient refrigerant has been evaporated to maintain the frost chamber at a low temperature for a more or less accurately determinable period of time, together with means for reestablishing the flow of fuel when the temperature of the frost chamber rises above a predetermined point.

An object of the present invention is to provide an improved fuel valve responsive both to conditions in the refrigerant boiler and in the frost chamber of a refrigerating system.

Another object of the invention is to provide a fuel valve responsive to conditions in a refrigerating system as above outlined, together with means responsive to a condition outside said refrigerator for controlling the action of the controlling means responsive to a condition in the refrigerant boiler.

Other objects include certain details of valve construction which are useful not only in refrigerating systems but in other applications, as will more clearly appear hereinafter.

In the accompanying drawing, Fig. 1 is a view partly in section through one form of my improved control mechanism including a diagrammatic illustration of a refrigerating system with which my control mechanism is adapted to be used; while Fig. 2 is a sectional view taken generally along the line 22 of Fig. 1.

Some of the features of my invention are valuable for other industrial uses than that illus- 'trated, but I have chosen to show my control mechanism as applied to a refrigerating system of the intermittent absorption type which generally includes a boilerflll to which external heat is applied by means of a burner ll supplied with fuel through a conduit 12. The refrigerant vapor from the boiler passes through conduit l3 and condensing andrectlfylng apparatus indicated. generally at M, and thence to an evaporating chamber l5 which is thus cooled and in turn supwhich rests against a shoulder 20 of the base member and suitable securing means comprising one or more machine screws 2! pass through the plate i9 and secureit to a portion of the valve casing so that the parts are held firmly in assembled position, as shown in Fig. l. The valve casing is provided with an inlet 22, an outlet 23 and a valve seat member 24 intermediate said inlet and outlet in which is formed a valve seat opening 25. Opposite sides of the valve casing are sealed in a fluid-tight manner by means of resilient diaphragms 26 and 2'! which are preferably of the snap type for the purpose hereinafter explained. These diaphragms may be secured in position in any suitable manner, that shown comprising cup-shaped members 28 and 29 which have a threaded connection with the main portion of the valve casing and serve to retain the diaphragms firmly in position. The diaphragm 27 supports a valve member 30 in position to 00- .act with the valve seat member'24. The particular method of mounting this valve member will be more fully described hereafter. I 'The inlet 22 is connected to a suitable source of fuel supply and the outlet 23 communicates by way of conduit 92 with the burner ll so that opening and closing of the valve initiates and cuts off the flow of fuel to the refrigerant boiler.

* Stem means is provided for actuation 'of the valve 30 and in the present embodiment'this comprises two separate parts indicated generally at 3| and 32. These parts with the valve open as shown'in Fig. 1, do not quite pontact at the point 33 but the distance between them is preferably a few thousandths of an inch. This distance is adjustable by a threaded connection 3| where the stem portion 3i passesv through the diaphragm 26. The stem portion 3| is rigidly connected with diaphragm 26 and mountedfor reciprocation in cup member 28 and means is provided for pushing downwardly upon this stem portion to open the valve. Stem portion 32 comprises a tubular member 34 which is rigidly coninner-wall of tube 34 has a threaded engagement with a screw 35-to which is connected a flexible valvestem 36 andby which valve 30 is raised.

' Thethreaded engagement between screw .35 and sleevetl so that bellows 59 rides on spring-63 v and itslower limit of. movement occurs when tube 34 permitsacloseadjustment of this valve anda second screw 31 maybe provided if desiredfor the purpose of lockingthis adjustment. The arrangement of valve stem means 3| and 32 in stem 36 are both effective to permit valve 38 to find its own seat in the opening 25 regardless of slight inequalities in the formation and assembly of the parts.

Means responsive to a condition in the fros chamber of the refrigerator is provided for opening the valve 30, the means shown comprising a bellows member 38 mounted within the base member H by means of a nipple 39 and an adjusting nut 48. The interior of the bellows 38 communicates by conduit 4| with a bulb 42 located in the frost chamber IS. The system 38-4l42 is filled with a suitable fluid which when heated causes bellows 38 to expand and when cooled permits bellows 38 to contract. Such devices are well known. The upper end of bellows 38 is connected with a rod 43 which in turn carries a member 44 which is pivotally connected at 45 with a leverlfi which in turn is pivotally mounted at 41 on a bracket. which is supported on the base in any convenient manner, the par- .lower end of which at 5| limits the upward I movement of bellows 38. Sleeve'58 is adjustably supported by a nut 52 which hasa threaded engagement with'the base [1 and compresses a. helical spring 53 against bellows 38 so that adjustment of nut 52 serves to regulate-the resistance against expansion of bellows 38 and-sodetermines the temperature necessary in frost oham-f ber Hi to actuate bellows. 38 and the connected mechanism. y t

l For a purpose later described,.the freeiend'lil of lever 48 is provided with a. one-way, operative The par-- ticular formillustrated comprises a plate155 =-in A which a slide is mounted forhorizontal re-.

connection with valve stem portion 3 I ciprocation. The slidev isbia'sed toward-theposishown in the, fullline position, and thereafter in the normal operation of the mechanism slide; member. 56 will. be slightly. raised and'leverf 46, -in returningfinacldckwisedirectidri'to thebroken line position, iwillengage the right-hand end of slide 56 and'move it toward the. left,..compressingjspring 51 'and-thusproviding an idle stroke of lever 48 when oscillating in a clockwise direction.

, Means responsivetoa condition in the refrigerant' boiler is provided 'for closing the valve 38. The means showncomprises a'bellows 59 which has a downwardly "extending stemill by which it is adjustably mounted in a sleeve 8| so that the bellows 59'ismounted for reciprocal movement relative to the base member H. To this end sleeve 6| passes through an opening in a v 2,071,019 nected with diaphragm 21 and mounted for rep of base i'l. This cup-shaped member serves also to retain a strong helical spring 83 extending about its outer periphery. :This' spring in turn support a plate 64' which is rigidly carried on plate 64 strikes the edge 85 'of .cup member 82.

The top member .66 of bellows, 5815 adopted to separate parts and the provision of the flexible" engage stem portion 32when the bellows expands for the purpose of closing valve 38. .Spring '63 I is strong enough to act as the lower abutment against-which bellowsu59 expands'to close valve -30. Bellows 59 communicates by conduit 51 with a additional F provision, if desired, -of one .or vmore openings luthrough the wall of the base member. In the particular type of refrigerating system Fun-shaped member 82 which lin turn has a l threaded engagement with the bottom member illustrated, fuel isf'cut .oifbeneath boiler-l8,.at-

a temperature which will. supply sumcient 're- Ifrigerant to maintain satisfactory conditions in the frost chamber I'B. for the desired interval of time. Where the atmosphere surrounding the refrigerator is at a' low temperature; fuel maybe cut off beneath boiler. lll'at a-muchlower temneath boiler'lll at a point satisfactory for cold.

inner and'outerbellows members which;are

.confinedbetween top and bottom .members- H and' -12 so asito providecajfluid-tight chamber;

therebetween. 'Througlia suitable'nipple; 13 the e ..;member "69 is filled withfluid 'andthe'nipplei'n =tion shown in Fig; -1 by means ofza spring51= and is retained on theiplate. SSS-by arlug58. construction provides a'pass-by mechanism so I that the end 54 of lever 48in moving in a counterclockwise direction from the'brokcn: line position "of Fig. 'l to the full line position. will press 1 downwardly/upon slide 56 and stem portion- 3| and will' thereafterclearsaid 'slideuportiomzas :is then' plugged. The fluid. in, member 69,-should preferably. be. one. which expandsnponincreasing 'temperature and contracts, with a decrease of bellows 59 tending to..:close" valve' 3lgfso that the. greater the external; temperature the'ehigh-' er'will be the point arrived at inboiler l8 necesfsary to cause closure 'of -'valve .38. The-structure for l, thus modifying the action. of :be'llows'259 by the bellows 89 comprises afsleeve. J4:--.whichl-'extends betweerr member :12, and Jplate; '64.1 '..':"It

1 will-thus be apparent that expansion of lbellows- Q 89Twill.,cause a downwardpressure onplate 84 1 thus compressingspring 63 more or less so, that bellows 59 will haveto expand to agreater extent in order to contact stem portion 32-to..close valve 38. p r

The action of my improvedcontrolmechanism through a cycle of operations is as'follows: 'Asl6 has risen to a point sufflcient toexpand bel-.

' can compress spring 63 only to the point where responsive to a condition in said frost chamber lows 38 against the action of spring 53 which has raised rod 43 and member 44 and oscillated lever 46 in a counterclockwise direction so that the'free end thereof 54 has depressed slide 56 and its associated stem portion 3i which, bearing against valve 38 at the point 33, has moved the valve to open. position. When snap diaphragms 26 and 21 passed their central or neutral point they snapped to the full line position shown in Fig. 1. Fuel is thus admitted through inlet 22, valve opening 25, outlet 23 and conduit l2 to burner Ii where it is lit by a suitable pilot valve. Heat is applied to boiler l causing a flow of vapor through conduit l3, condenser II, to evaporating chamber i5. This continues until the temperature rises sufliciently in boiler ID to expand bellows 59, the amount of whichwill depend upon the modifying action of bellows 68 at any given temperature, to a point where stem member 32 rises past the neutral point of diaphragms 26 and 21, whereupon valve 30 snaps to its shut position and is maintained therein by the tension upwardly on diaphragm 21. The movement upward of stem portion 32 and valve 30. will of course raise stem portion 3| and slide 56 to the broken line position of Fig. 1. Upon the cessation of evaporating actionin boiler l0 and the evaporation and cooling consequent upon the evaporation of vapor in member l5, frost chamber I 6 will be cooled, bulb 42 and corresponding bellows 38 will be cooled and bellows 38 will contract, thus oscillating lever 46 in a. clockwise direction to the broken line position of Fig.

1 ready to perform another operation. In moving from its full line position to its brokenline position in Fig. 1, lever 46 will move slide 56 to the left in an idle stroke and spring 51 will then return the slide to its right hand position ready to be engaged by the free end 54 of lever 46 when the frost chamber again becomes sufliciently warm.

The provision of stop 65 for limiting the movement of plate 64 which in turn limits the expansion necessary in bellows 58 to close valve 3!] acts as a safety device to prevent dangerous conditions in the refrigerant boiler ill. That is to say, even under the hottest external conditions bellows 69 through its action on sleeve 74 plate 64 contacts the edge 65 of cup member 62. This point is so adjusted that the temperature necessary in boiler iii to expand the system 59--6l--68 to valve closing position corresponds to a. safe pressure condition in boiler l6.

What I claim is:

1. Control mechanism for a refrigerating system of the intermittent absorption type having a refrigerant boiler, a fuel burner therefor and a frost chamber, comprising a valve controlling the flow of fuel to said burner, a bellows responsive to a condition in said frost chamber for opening said valve, a bellows movable in response to a condition in saidboiler for closing said valve, and means responsive to an increasing temperature condition outside said system for increasing the movement required of said second named bellows to close said valve.

2. Control mechanism as in claim 1 including means limiting the movement of said last named means at a predetermined point.

3. Control mechanism for a refrigerating system of the intermittent absorption type having a refrigerant boiler, a fuel burner therefor and a frost chamber, comprising a-valve'controlling the flow of fuel to said burner, control means for opening said 'valve, control means movable in response to a condition in said boiler for closing said valve. and means responsive to an increasing temperature condition outside said system for increasing the movement required of said second named control means to close said valve.

4. Control mechanism comprising a valve casing having its opposite sides sealed by resilient diaphragms, there being inlet and outlet openings through said casing and a valveseat member intermediate said openings, stems having operative connections with said diaphragms, said stems having adjacent ends adapted to mutually contact, a valve member on one of said stems adapted to coact withsaid seat member, temperature responsive means for moving one of said stems in valve opening direction, and another-temperature responsive means for moving 1 the other of said stems in valve closing direction.

5. Control mechanism as in claim 4 in which said resilient diaphragms are snap diaphragms having one position adapted to hold said valve member in contact with its coacting seat member.

6. Control mechanism as in claim 4 in which said valve member is resiliently mounted on one of said stems whereby to adjust itself to its coacting seat member.

'7. Control mechanism as in claim 4 and including a third temperature responsive means arranged to have a controlling effect on one of said named temperature responsive means.

8. Control mechanismas in claim 4 in which the means for moving one of said stems in valve opening direction has a connection with said stem operative in valve opening direction only.

9. Control mechanism comprising a valve casing having its opposite sides sealed by resilient diaphragms, there being inlet and outlet openings through said casing and a valve seat member intermediate said openings, stems having operative connections with said diaphragms, said stems having adjacent ends adapted to mutually contact, a valve member on one of said stems adapted to coact with said seat member, a bellows for moving one of said stems in valve opening direction, and a second bellows for moving the other of said stems in valve closing direction.

10. Control mechanism comprising a valve, a bellows having operative connections for opening said valve, a second bellows having operative connections for closing said valve, and a third bellows arranged to modify the action of said second bellows.

11. Control mechanism comprising a valve, means for opening said valve, a bellows expansible for closing .said valve, means forming a movable abutment against which said bellows expands, and bellows means for moving said abutment means.

12. Control mechanism comprising, a valve includinga casing having an inlet and an outlet and a valve seat member intermediate said inlet and outlet. a valve member in said casing adapted to coact with said seat member, stem means for actuating said valve member, temperature responsive means for moving said stem means in valve closing direction, a second temperature responsive means for moving said stem means in valve opening direction, said last named temperature responsive means including a lever adapted to contact said stem means, and apassby mechanism between said lever and stem means when said lever moves in one direction only and whereby said lever performs an idle movement 'in the opposite direction.

valve, means responsive to a temperature rise in the frost chamber of said refrigerator for "providing'means for actuating-said stem means opening said valve, means responsive to a temperature rise in the refrigerant boiler of said refrigerator for closing said valve, and means responsive to increased temperature outside said refrigerator for increasing the action of said last- 5 named means necessary to close said valve.

FREIADRICK E. BEEBE. 

